In the field of Internet, when a piece of new news appears, it is required to compare this news with existing news to determine which news among the existing news are related to the new news, so that the related news may be recommended to a user together with the new news when the user is viewing the news.
The number of the existing news is huge, and each piece of new news needs to be compared with all the existing news, which results in a huge calculation amount and a low efficiency in calculating relevance among the news.